Therefore the skin puncture is done as shown at the hollow of the delto-pectoral triangle, about 1-2 finger-breadths below from the clavicle at its junction between the middle third and lateral third (roughly at its “bend”). It should be realized that the needle will be traveling through the upper aspect of the pectoralis major muscle (through its clavicular head)
The puncture needle is slowly advanced towards the shaft of the clavicle (at about an 20-30 degree angle to the skin) and once it hits the clavicle, the needle is slightly withdrawn and angulated (increased angle of attack to skin surface ) more so that the tip is under the clavicle. Then, the direction of the needle is changed so that now the tip aims towards the supra-sternal notch. The needle is slowly advanced in that direction (now at a skin angle of 20 – 30 degrees) with gentle suction to see whether it punctures the vein – whence dark venous blood would be aspirated. Once blood is aspirated, the needle is steadied and liberal aspiration of blood is done to ensure good access in to the vein. Thereafter the syringe is removed and guide-wire advanced in to the lumen.
Subclavian Puncture Steps :
Once the needle tip hits the bone, the needle is slightly withdrawn and the angle of attack is increased as to enter the underside of the clavicle. As soon as one feels the underside of the clavicle, advancement should be stopped and direction of the needle change to point towards the supra-sternal notch.
Gentle suction is applied as the needle is advanced. (Vigorous suction should be avoided as it will draw fat / muscle debris in to the lumen and obstruct it)
At one point one will enter the vein and blood will be visible in the syringe with suction.A generous amount of blood should be aspirated to confirm venous access.
If the vein is not accessed despite full advancement of the needle, one can try sight variation in depth of penetration. However, the risk of pneumothorax is high in this region and it is recommended that an alternative x-ray guided approach be used.